Difference between @@IDENTITY, SCOPE_IDENTITY, IDENT_CURRENT

In most of our application scenario, we need to get latest inserted row information through SQL query. And for that, we have multiple options like:

• @@IDENTITY
• SCOPE_IDENTITY
• IDENT_CURRENT

All three functions return last-generated identity values. However, the scope and session on which last is defined in each of these functions differ.

Compare

@@IDENTITY

It returns the last identity value generated for any table in the current session, across all scopes.
Let me explain this... suppose we create an insert trigger on table which inserts a row in another table with generate an identity column, then @@IDENTITY returns that identity record which is created by trigger.

SCOPE_IDENTITY

It returns the last identity value generated for any table in the current session and the current scope.
Let me explain this... suppose we create an insert trigger on table which inserts a row in another table with generate an identity column, then SCOPE_IDENTITY result is not affected but if a trigger or a user defined function is affected on the same table that produced the value returns that identity record then SCOPE_IDENTITY returns that identity record which is created by trigger or a user defined function.

SCOPE_IDENTITY and @@IDENTITY will return last identity values generated in any table in the current session. However, SCOPE_IDENTITY returns values inserted only within the current scope; @@IDENTITY is not limited to a specific scope.

For example, you have two tables, T1 and T2, and an INSERT trigger defined on T1. When a row is inserted to T1, the trigger fires and inserts a row in T2. This scenario illustrates two scopes: the insert on T1, and the insert on T2 as a result of the trigger.

@@IDENTITY will return the last IDENTITY column value inserted across any scope in the current session, which is the value inserted in T2.
SCOPE_IDENTITY() will return the IDENTITY value inserted in T1, which was the last INSERT that occurred in the same scope. The SCOPE_IDENTITY() function will return the NULL value if the function is invoked before any insert statements into an identity column occur in the scope.

IDENT_CURRENT

It returns the last identity value generated for a specific table in any session and any scope.
In other words, we can say it is not affected by scope and session, it only depends on a particular table and returns that table related identity value which is generated in any session or scope.

IDENT_CURRENT is not limited by scope and session; it is limited to a specified table. IDENT_CURRENT returns the value generated for a specific table in any session and any scope.